This application claims the priority of Korean Patent Application No. 10-2003-0077574 filed on Nov. 4, 2003 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a liquid crystal display device having a touch screen function. More particularly, the present invention is directed to a liquid crystal display device that is constructed to have a touch screen function using variation in liquid crystal cell capacitance due to variation in liquid crystal cell gaps.
2. Description of the Related Art
Generally, a liquid crystal display device is a display device for obtaining desired image signals by applying an electric field to a liquid crystal material that fills a gap between two substrates and has an anisotropic dielectric constant and controlling the intensity of the electric field, thereby adjusting the amount of light that is transmitted through the substrates.
Recently, touch screen panels (TSP) have become widely used as an input means. A TSP is a device that reads user's input in the form of a coordinate value and receives information corresponding to the read coordinate value.
Heretofore, it is common that an additional touch panel is stacked and attached to a surface of a liquid crystal panel so as to add a touch screen function to a liquid crystal display (LCD) device.
However, the LCD device in which a touch panel is attached to the liquid crystal panel as mentioned above cannot provide high quality images, because the images are excessively floated due to light parallax occurring when light for displaying images reproduced on the liquid crystal panel is transmitted through the touch panel.
Furthermore, since the additional process of attaching the two panels to each other is required, the number of processes increases. Therefore, there are problems in that it takes a lot of time to fabricate an LCD device while manufacturing costs also increase.